如何使用 Vuex 进行撤消/重做?我正在开发一个非常复杂的应用程序,Vue 开发工具帮助我在状态之间切换了很多,所以我希望我的应用程序上有这个功能。我怎样才能做到这一点?
我已经实现了撤消重做,如下所示:
1( 为 Vuex 创建一个插件
const undoRedoPlugin = (store) => {
// initialize and save the starting stage
undoRedoHistory.init(store);
let firstState = cloneDeep(store.state);
undoRedoHistory.addState(firstState);
store.subscribe((mutation, state) => {
// is called AFTER every mutation
undoRedoHistory.addState(cloneDeep(state));
});
}
2(使用该插件
new Vuex.Store({
...
plugins: [undoRedoPlugin]
});
3(在撤消重做历史记录中保存状态的历史记录
class UndoRedoHistory {
store;
history = [];
currentIndex = -1;
init(store) {
this.store = store;
}
addState(state) {
// may be we have to remove redo steps
if (this.currentIndex + 1 < this.history.length) {
this.history.splice(this.currentIndex + 1);
}
this.history.push(state);
this.currentIndex++;
}
undo() {
const prevState = this.history[this.currentIndex - 1];
// take a copy of the history state
// because it would be changed during store mutations
// what would corrupt the undo-redo-history
// (same on redo)
this.store.replaceState(cloneDeep(prevState));
this.currentIndex--;
}
redo() {
const nextState = this.history[this.currentIndex + 1];
this.store.replaceState(cloneDeep(nextState));
this.currentIndex++;
}
}
const undoRedoHistory = new UndoRedoHistory();
4(使用它
undoRedoHistory.undo();
...
undoRedoHistory.redo();
如果您的状态大小不大,那么克隆该状态是一个很好的方法。
参见:https://vuex.vuejs.org/en/api.html
您可以轻松地使用 subscribe(handler: Function)
注册一个函数,该函数将给定存储中所需的所有状态保存在数组中。
然后,您可以通过将它们作为参数提供给replaceState(state: Object)
来使用该数组中的任何保存状态。